Authorities are investigating a suspicious briefcase found in a garbage can at the Mandeville post office on U.S. 190 near St. Ann. The St. Tammany Parish Sheriff's Office bomb squad is on the scene, as well as officers from the Mandeville Police Department, the FBI and the Bureau of Alcohol, Tobacco and Firearms.

Mandeville police Lt. Gerald Sticker said an employee at the post office noticed what was described as a "brand new briefcase'' in the garbage can around 6:30 Wednesday morning. The post office alerted authorities.

The 12 employees at the post office were evacuated, as were the nearby Walgreens and CVS stores, which were the only area stores open at that hour, Sticker said.

Suspicious bag forces evacuation around Mandeville Post OfficeA member of the bomb squad positions a suspicious bag in the parking lot of the Mandeville Post Office and readies equipment to explode with by firing a shotgun into it, according to Mandeville police. The Police, St. Tammany Sheriff's Department, ATF and the FBI worked together as they investigated the suspicious package found by a custodian emptying garbage cans at the Mandeville Post Office, closing a section of hwy. 190 and evacuating an area past Blue Harbor and Macaroni Grill, Wednesday April17, 2013. The bag was found to hold only trash, but the custodian, David Lowe found it suspicious because of how it was placed in the can and that the bag looked new. He also said that because of the events in Boston it was a good idea to call the police.

U.S. 190 and several other streets in the area were then closed.

The St. Tammany Parish school system said four buses carrying students are now parked in neighborhoods outside the evacuation zone, waiting until the area has been cleared by police. Schools spokeswoman Meredith Mendez said the schools are working closely with police. It wasn't immediately clear to which schools those buses were driving.